grenademan

Even if you didn't told me how to stop it, you still helped me a lot!! thanks!!

Hope you guys can help me out well, I just got a new flashacrd ("DS One") and loaded it with games one of them was Pokemon Diamond since my friend wanted a pokemon save too, I put in Pokemon Pearl. Now, I played my save and got to the first GYM and let my friend play for a while whan I loaded my game again, it returned back to an earlyer save! so I played again and got till the 2nd GYM this time, wondering what happened then I thought that mybe It's my friends game that massed up my save, I loaded Phonix wright, played for a while and returned to my Diamond, no change then, I loaded my friends game (only loaded his save) and when I returned to mine, it returned back again... so, can it be that the two pokemon games don't work together? even if the games has different file name? or is it something else? please help me guys